A voltage-controlled tunable distributed RC filter

A new type of voltage-controlled tunable distributed RC filter is described by the type metal-insulator-semiconductor-metal. Tuning is attained by field-effect control of the capacitance by a bias voltage, independently of the distributed resistance. Results are given for evaporated thin-film NiCr-Y/SUB 2/O/SUB 3/-CdS-Al filters, together with illustrative applications to tunable RF networks.